Variable declaration rules

[onbjerg]

Describe the feature

We currently do not have most of the checks for variable declarations in https://github.com/argotorg/solidity/blob/73712a01b2de56d9ad91e3b6936f85c90cb7de36/libsolidity/analysis/TypeChecker.cpp#L475-L596

We need to implement these. The entrypoint for this is in

solar/crates/sema/src/typeck/checker.rs

Lines 582 to 596 in 38f086a

	#[must_use]
	fn check_var_(&mut self, id: hir::VariableId, expect: bool) -> Ty<'gcx> {
	let var = self.gcx.hir.variable(id);
	let _ = self.visit_ty(&var.ty);
	let ty = self.gcx.type_of_item(id.into());
	if let Some(init) = var.initializer {
	// TODO: might have different logic vs assignment
	self.check_assign(ty, init);
	if expect {
	let _ = self.expect_ty(init, ty);
	}
	}
	// TODO: checks from https://github.com/ethereum/solidity/blob/9d7cc42bc1c12bb43e9dccf8c6c36833fdfcbbca/libsolidity/analysis/TypeChecker.cpp#L472
	ty
	}

Additional context

No response

[Jds-23]

Gm, can I work on this?